feat(device): 新增设备定位查询接口并修复定位数据存储问题

- 新增 GET /{sn}/location 接口，支持网页端查询设备最新定位信息
- 新增 DeviceLocationVO 视图对象用于返回定位数据
- 在 LocationService 中实现 getLatestBySn 方法
- 修复 map_error 字段类型错误：从 INT 改为 VARCHAR(255)
- 修复移动端上报定位时 lastSuccessfulTime 缺失问题，由服务端统一写入

src/main/java/com/youlai/boot/device/controller/DeviceOpsController.java

@@ -7,9 +7,12 @@ import com.youlai.boot.common.result.Result;
 import com.youlai.boot.device.model.entity.SnDeviceInfo;
 import com.youlai.boot.device.model.form.AppActionForm;
 import com.youlai.boot.device.model.form.DeveloperForm;
+import com.youlai.boot.device.model.vo.DeviceLocationVO;
 import com.youlai.boot.device.model.vo.DevicePageVO;
 import com.youlai.boot.device.service.DeviceService;
+import com.youlai.boot.device.service.LocationService;
 import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
@@ -30,6 +33,7 @@ import org.springframework.web.bind.annotation.*;
 public class DeviceOpsController {
 
     private final DeviceService deviceService;
+    private final LocationService locationService;
 
     @Operation(summary = "获取SN绑定激活信息")
     @GetMapping("/{sn}/info")
@@ -96,6 +100,13 @@ public class DeviceOpsController {
         return Result.judge(result);
     }
 
+    @Operation(summary = "获取设备最新定位信息", description = "返回设备最近一次上报的定位信息，用于网页端展示百度地图")
+    @GetMapping("/{sn}/location")
+    public Result<DeviceLocationVO> getLocation(@Parameter(description = "设备序列号", required = true) @PathVariable String sn) {
+        DeviceLocationVO location = locationService.getLatestBySn(sn);
+        return Result.success(location);
+    }
+
     @Operation(summary = "设备重置")
     @PostMapping("/restore")
     @Log(module = LogModuleEnum.DEVICE, value = ActionTypeEnum.RESTORE)

src/main/java/com/youlai/boot/device/controller/MobileController.java

@@ -406,6 +406,8 @@ public class MobileController {
             SnLocation location = new SnLocation();
             BeanUtils.copyProperties(locationReq, location);
             location.setSn(sn);
+            // 上次定位成功时间由服务端统一写入，避免移动端时间不准或 LocalDateTime 序列化格式不一致导致为空
+            location.setLastSuccessfulTime(LocalDateTime.now());
 
             SnLocation existingLocation = locationService.lambdaQuery()
                     .eq(SnLocation::getSn, sn)

src/main/java/com/youlai/boot/device/model/vo/DeviceLocationVO.java

@@ -0,0 +1,69 @@
+package com.youlai.boot.device.model.vo;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Data;
+
+import java.io.Serializable;
+import java.time.LocalDateTime;
+
+/**
+ * 设备定位信息视图对象
+ */
+@Schema(description = "设备定位信息")
+@Data
+public class DeviceLocationVO implements Serializable {
+
+    @Schema(description = "设备序列号")
+    private String sn;
+
+    @Schema(description = "国家")
+    private String country;
+
+    @Schema(description = "国家代码")
+    private String countryCode;
+
+    @Schema(description = "省")
+    private String province;
+
+    @Schema(description = "市")
+    private String city;
+
+    @Schema(description = "城市代码")
+    private String cityCode;
+
+    @Schema(description = "区/县")
+    private String district;
+
+    @Schema(description = "街道")
+    private String street;
+
+    @Schema(description = "门牌号")
+    private String streetNumber;
+
+    @Schema(description = "详细地址")
+    private String address;
+
+    @Schema(description = "区域编码")
+    private String adCode;
+
+    @Schema(description = "镇")
+    private String town;
+
+    @Schema(description = "镇级行政区划编码")
+    private String townCode;
+
+    @Schema(description = "位置描述（百度周边语义化描述）")
+    private String locationDescribe;
+
+    @Schema(description = "经度")
+    private String longitude;
+
+    @Schema(description = "纬度")
+    private String latitude;
+
+    @Schema(description = "定位失败原因，成功时为 '-'")
+    private String mapError;
+
+    @Schema(description = "上次定位成功时间")
+    private LocalDateTime lastSuccessfulTime;
+}

src/main/java/com/youlai/boot/device/service/LocationService.java

@@ -2,10 +2,18 @@ package com.youlai.boot.device.service;
 
 import com.baomidou.mybatisplus.extension.service.IService;
 import com.youlai.boot.device.model.entity.SnLocation;
+import com.youlai.boot.device.model.vo.DeviceLocationVO;
 
 /**
  * 设备定位服务接口
  */
 public interface LocationService extends IService<SnLocation> {
 
-}
+    /**
+     * 根据设备 SN 获取最新一条定位信息
+     *
+     * @param sn 设备序列号
+     * @return 最新定位信息视图对象，不存在时返回 null
+     */
+    DeviceLocationVO getLatestBySn(String sn);
+}

src/main/java/com/youlai/boot/device/service/impl/LocationServiceImpl.java

@@ -1,10 +1,13 @@
 package com.youlai.boot.device.service.impl;
 
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
 import com.youlai.boot.device.mapper.LocationMapper;
 import com.youlai.boot.device.model.entity.SnLocation;
+import com.youlai.boot.device.model.vo.DeviceLocationVO;
 import com.youlai.boot.device.service.LocationService;
 import lombok.RequiredArgsConstructor;
+import org.springframework.beans.BeanUtils;
 import org.springframework.stereotype.Service;
 
 /**
@@ -13,4 +16,20 @@ import org.springframework.stereotype.Service;
 @Service
 @RequiredArgsConstructor
 public class LocationServiceImpl extends ServiceImpl<LocationMapper, SnLocation> implements LocationService {
-}
+
+    @Override
+    public DeviceLocationVO getLatestBySn(String sn) {
+        SnLocation location = this.getOne(
+                new LambdaQueryWrapper<SnLocation>()
+                        .eq(SnLocation::getSn, sn)
+                        .orderByDesc(SnLocation::getLastSuccessfulTime)
+                        .last("LIMIT 1")
+        );
+        if (location == null) {
+            return null;
+        }
+        DeviceLocationVO vo = new DeviceLocationVO();
+        BeanUtils.copyProperties(location, vo);
+        return vo;
+    }
+}